Complaint Regarding Poor Customer Service and Unjustified Refusal of Check-in

I am writing to formally lodge a complaint regarding my recent experience with Safair, which has left me extremely dissatisfied. On 14th Nov, I arrived at the Safair check-in counter at 5:45 AM for my flight, only to be informed that I was too late to check in. The staff member at the counter confirmed that it was exactly 5:45 AM and stated that I should have arrived earlier, even though I was within the stated check-in window. She then claimed boarding had already started. To further escalate the situation, I approached Team Leader Keshni Adojah, explaining that I was on a business trip and needed to catch the flight. I also informed her that my colleague, who was already at the gate, confirmed that boarding had not yet begun. Despite this, she dismissed my request to take my luggage with me and, without weighing it, arbitrarily claimed my bag was too large to carry onboard. What followed was even more troubling. Keshni confirmed that all seats had been sold out, including mine. This led me to believe that my pre-booked, priority paid seat had been sold to a standby passenger. When I pointed out that I arrived on time and had been informed by the check-in staff at 5:45 AM, Keshni wanted me to point out the staff at the baggage counter rather than addressing my concerns. As a result, I was forced to pay an additional R570 for a flight at 8:30 AM to Johannesburg, causing me to be three hours late for a crucial business meeting. This experience has caused significant disruption to my professional obligations. I am a frequent traveller with Safair and have never encountered such poor customer service or confusion regarding check-in procedures. I was never informed that I needed to arrive before the baggage check-in cut-off time, and I am extremely disappointed with how this matter was handled. I respectfully request an explanation for the circumstances that led to my being denied boarding and the poor handling of my case. Additionally, I believe some form of compensation for the inconvenience and additional costs incurred would be appropriate.